TY - JOUR
T1 - Experimentally informed micromechanical modelling of cement paste
T2 - An approach coupling X-ray computed tomography and statistical nanoindentation
AU - Zhang, Hongzhi
AU - Šavija, Branko
AU - Luković, Mladena
AU - Schlangen, Erik
N1 - Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.
PY - 2019/1/15
Y1 - 2019/1/15
N2 - This work proposes a method for numerically investigating the fracture mechanism of cement paste at the microscale based on X-ray computed tomography and nanoindentation. For this purpose, greyscale level based digital microstructure was generated by X-ray microcomputed tomography with a resolution of 2 μm/voxel length. In addition, statistics based micromechanical properties (i.e. Young's modulus and hardness) were derived from the grid nanoindentation test which was set to have an interaction volume the same as the resolution of the digital microstructure. A linear relationship between the two probability density functions of greyscale level and local Young's modulus was assumed and verified by the two-sample Kolmogorov-Smirnov (K–S) statistic. Based on this assumption, the fracture and deformation of a digital cubic volume with a dimension of 100 μm under uniaxial tension was simulated using a lattice fracture model. In addition, the influence of heterogeneity on fracture response was studied. Furthermore, the proposed method was compared with the results obtained from a traditional approach used previously by the authors in which discrete phases (capillary pore, anhydrous cement clinker, outer and inner hydration products) were considered. The two methods show similar crack patterns and stress-strain responses. The proposed method is regarded more promising as it captures also the gradient of material properties (within the discrete phases) in the cement paste.
AB - This work proposes a method for numerically investigating the fracture mechanism of cement paste at the microscale based on X-ray computed tomography and nanoindentation. For this purpose, greyscale level based digital microstructure was generated by X-ray microcomputed tomography with a resolution of 2 μm/voxel length. In addition, statistics based micromechanical properties (i.e. Young's modulus and hardness) were derived from the grid nanoindentation test which was set to have an interaction volume the same as the resolution of the digital microstructure. A linear relationship between the two probability density functions of greyscale level and local Young's modulus was assumed and verified by the two-sample Kolmogorov-Smirnov (K–S) statistic. Based on this assumption, the fracture and deformation of a digital cubic volume with a dimension of 100 μm under uniaxial tension was simulated using a lattice fracture model. In addition, the influence of heterogeneity on fracture response was studied. Furthermore, the proposed method was compared with the results obtained from a traditional approach used previously by the authors in which discrete phases (capillary pore, anhydrous cement clinker, outer and inner hydration products) were considered. The two methods show similar crack patterns and stress-strain responses. The proposed method is regarded more promising as it captures also the gradient of material properties (within the discrete phases) in the cement paste.
UR - http://www.scopus.com/inward/record.url?scp=85054324303&partnerID=8YFLogxK
UR - http://resolver.tudelft.nl/uuid:2b36bb9f-b4e3-4585-8ef0-2631e7a4f74a
U2 - 10.1016/j.compositesb.2018.08.102
DO - 10.1016/j.compositesb.2018.08.102
M3 - Article
AN - SCOPUS:85054324303
SN - 1359-8368
VL - 157
SP - 109
EP - 122
JO - Composites Part B: Engineering
JF - Composites Part B: Engineering
ER -